1. Field of the Invention
The present invention relates to a phosphor used in a display device such as an LED, CRT, PDP, FED, and EL, and a lighting unit such as a vacuum fluorescent display and fluorescent lamp. More particularly, the present invention relates to a phosphor and a production method of the same, the phosphor being suitable for an LED, a light source, a lighting unit and the like each of which has a light emitting portion and a phosphor of ultraviolet-blue light or the like and emits visible light or white light by cooperation of both the light emitting portion and the phosphor, and to a light is source and an LED using the phosphor.
2. Description of the Related Art
An LED, a light source and a lighting unit are known, which emit white light by a combination of a light emitting portion constituted of a light emitting element which emits blue or ultraviolet light by itself and a phosphor which has an excitation band in the ultraviolet-blue wavelength region generated from the light emitting element and, upon excitation by the light of that wavelength region, emits fluorescent light of a predetermined wavelength region.
As the phosphor used in the LED and the like, phosphors represented by general formulas Y2O2S:Eu, La2O2S:Eu, 3.5MgO.0.5MgF2.GeO2:Mn, and (La, Mn, Sm)2O2S.Ga2O3 are known as a phosphor which emit red fluorescent light, phosphors represented by general formulas ZnS:Cu,Al, SrAl2O4:Eu, and BAM:Eu,Mn are known as a phosphor which emits green fluorescent light, a phosphor represented by a general formula YAG:Ce is known as a phosphor which emits yellow fluorescent light, and phosphors represented by general formulas BAM:Eu, Sr5(PO4)3Cl:Eu, ZnS:Ag, and (Sr, Ca, Ba, Mg)10(PO4)6 Cl:Eu are known as phosphors which emit blue fluorescent light. Then, there are suggested an LED, a light source and a lighting unit which emit white or monochromatic light using a combination of these phosphors and a light emitting element which emits blue or ultraviolet light by itself.
Furthermore, in recent years, as the phosphor having the excitation band in the ultraviolet-blue wavelength region, there are suggested an oxynitride glass phosphor (for example, refer to Patent Document 1), a phosphor having a sialon as a host material (for example, refer to Patent Documents 2, 3 and 4), and a phosphor including nitrogen of a silicon nitride group or the like (for example, refer to Patent Documents 5 and 6), and there are suggested an LED, a light source and a lighting unit which emit white or monochromatic light using a combination of these phosphors and a light emitting element which emits blue or ultraviolet light by itself.
[Patent Document 1] Japanese Patent Application Laid-open No. 2001-214162
[Patent Document 2] Japanese Patent Application Laid-open No. 2003-336059
[Patent Document 3] Japanese Patent Application Laid-open No. 2003-124527
[Patent Document 4] Japanese Patent Application Laid-pen No. 2004-67837
[Patent Document 5] Translated National Publication of Patent Application No. 2003-515655
[Patent Document 6] Japanese Patent Application Laid-open No. 2003-277746